What is the negative predictive value of a negative extended myositis panel in dermatomyositis patients?
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2 Answers
Mednet Member
Rheumatology · Emory University
The short answer is "not great, but it depends" since the more nuanced answer is contingent on:
- the constellation of myositis-specific antibodies (MSA) included on the panel,
- the nitty-gritty of how the commercial lab is checking the MSA included (this detail can change between vendors, or even ...
Mednet Member
Dermatology · UCLA Health
The negative predictive value of the panel is not high. About half of my dermatomyositis patients have negative antibodies. Diagnosis is made based on clinical presentation with compatible/classic signs, skin/muscle pathology, MRI, and muscle enzymes in addition to antibodies. Of note, about 80% of ...